Method of printing



June 17, 1941. c. L WALTER METHOD OF PRINTING Filed April 8, 1959 5 Sheets-Sheet l i- Ulllllll Inventor A itorneys June 17, 1941. c. L. WALTER METHOD OF PRINTING Filed April 8, 1939 5 Sheets-Sheet 2 Inventor @L CLARENCE LEE TVA/J52,

Attorneys June 17, 1941. c. L. WALTER METHOD OF PRINTING Filed April 8, 1939 3 Sheets-Sheet 3 MR E T L m E E L a m R m I Atloi'neys Patented June 17, 1941 UNITED STATES PATENT OFFICE METHOD OF PRINTING Clarence Lee Walter, St. Louis, Mo.

Application April 8, 1939, Serial No. 266,814

2 Claims.

out any change in the basic design or equipment of the usual platen job press.

Other and subordinate objects are also comprehended by my invention all of which together with the precise nature of my improvements will become readily apparent when the succeeding description and claims are read in conjunction with the drawings accompanying and forming a part of the specification.

In said drawings:

Figure 1 is a view in top plan illustrating a platen job press equipped for the practice of my improved method.

Figure 2 is a view in perspective illustrating how the stencil sheet is mounted in the stencil frame and press preparatory to printing.

Figure 3 is a view in transverse section taken on the line 3-3 of Figure 2 looking in the direction of the arrows.

Figure 4 is a view in side elevation further illustrating how the stencil frame is mounted in the press.

Figure 5 is a view in perspective pad.

Figure 6 is a view in section of said pad.

Figure 7 is .a view in vertical section, partly in front elevation, taken on the line 1-1 of Figure 4.

Figure 8 is a view partly in side elevation and partly in vertical section taken on the line 8-8 of Figure 7.

Figure 9 is a view partly in transverse section and partly in top plan illustrating how the inking pad fits into the stencil frame to press against the stencil sheet,

Describing now my invention in detail with reference to the drawings by numerals, my improved method comprehends printing from a stencil such as are used in mimeographed work.

I prefer to utilize a type of such stencils which when finished consist of a sheet of Yoshino fibre stencil paper covered with an insoluble coating except for the image from which said coating is dissolved away in the process of making the stencil leaving only the bare fibres of the paper.

of the inking Since the process of making such stencils is immaterial to the present invention it need not be explained herein.

According to my invention a photographic stencil sheet of the above described type is touched up with any suitable retouching compounds so that areas not desired to be printed are painted out and any weak areas to be printed are painted up to give greater resistance in printing. Large open fibre areas are painted with a suitable" compound to stiffen the fibres in such areas so as to impart to the same greater resistance against pressure in printing.

The stencil sheet, represented at l, in the drawings, is mounted in a stencil frame 2 of semirigid material, such as cardboard, having an opening 3 formed therein slightly smaller than the stencil sheet I over which said sheet is secured by gluing the edges thereof to said frame around said opening 3, as best shown in Figure 9. The open frame 2 contitutes a reinforcement on one side of the stencil sheet around the printing area solely.

The stencil frame 2, with the stencil sheet i therein, is next attached in a pressof the usual job printing type having the platen 4 operated by the usual operating mechanism, represented at 5, to close onto a printing form 6 locked in the press in the usual manner to be inked by the inking rollers, not shown. In such presses, as will be understood, the platen 4 carries a pair of work or sheet grippers 9 operative, by mechanism represented at ID, to clamp opposite edges of the work sheet (not shown) to the platen 4 prior to closing of the press and to release said sheet when the-press is fully opened.

The stencil frame 2 is attached to one of said grippers 9 with the stencil sheet I facing the platen 4 and between the frame 2 and the platen 4 so that when said grippers assume clamping position, said sheet I will lie flat against a work sheet imposed on said platen. For this purpose the stencil frame 2 is secured to the inner side edge of said one gripper 9 to extend inwardly therefrom over the work sheet preferably by means of a pair of thin, semirigid, resilient clips Ii spanning the gripper -9 and the upper and lower edges of the stencil frame 2 and clampingly engaging the gripper and frame so as to prevent accidental displacement of the latter.

An inking pad I2 for the stencil sheet I is provided comprising a block [3 of wood of the proper size to fit, with a slight clearance, into the stencil frame 2, said block being covered with a thin layer I4 of sponge rubber faced with a layer.

ll of smooth rubber. The described inking pad II is clamped in the printing form covered side outermost by any of the usual clamping means adjunctive to such forms, as represented at It, and so as to press the stencil sheet I against the work sheet when the press is closed. The inking pad is of the proper thickness to be type high so that it and the stencil sheet I may be used in printing with type II clamped to the form I for job printing.

As will be understood, when the press opens up the inking rollers, not shown, will distribute ink over the inking pad I2 and when the press closes up for the impression, the rubber layer ll will enter the stencil frame 2, press against the stencil sheet I and thereby force ink through the fibre area of the image, or pattern, onto the work sheet imposed on the platen 4 so as to print the image on said work sheet. The inking pad I2 may be built up in the form 6 to vary the tone of printing as desired and as represented at IS. The stencil sheet I may be run separately, or concurrently, with type printing. To remove the stencil frame 2 and stencil sheet I, it is merely necessary to detach the clips I I.

The foregoing will, it is believed, suihce to impart a clear understanding of my invention.

Manifestly, the invention, as described, is susceptible of modification without departing from the inventive concept and right is herein reserved to such modifications as fall within the scope of the subjoined claims.

What I claim is:

1. The herein described method 01' printing on a work sheet in a platen press including printing type comprising constructing a stencil sheet with an image forming area smaller than said sheet,

treating said stencil sheet to stiiien said area,

reinforcing one side of the stencil sheetaround said area solely, imposing the other side or said stencil sheet against the work sheet, simultaneously applying pressure against the work sheet in the direction of the stencil sheet and pressure against the image forming area in the direction of the work sheet and within the confines oi the reinforcement and in a plane type high, whereby the ink will be forced under such pressure through said area onto said work sheet to print the image simultaneously with the printing by the type.

2. The herein described method of printing on a work sheet in a platen press including printing type comprising constructing a stencil sheet with an image forming area smaller than said sheet, treating said stencil sheet to stiffen said area. reinforcing one side of the stencil sheet around said area solely, imposing the other side of said stencil sheet against the work sheet, simultaneously app y ng pressure against the work sheet in the direction of the stencil sheet and yielding pressure against the image forming area in the direction ,oh the work sheet and within the confines of the reinforcement and in a plane type high. and inking the image forming area simultaneously with such application of pressure, whereby the ink will be forced under such pressure through said area onto said work sheet to print the image simultaneously with the printing by the type. CLARENCE LEE WALTER. 

